I thought that I'd update this thread now that the mystery of why my D800 died during my 13 hour drive to SW France on 26 December 2012 - RIP - has been solved. All became clear when I reached into the bottom of my camera bag to retrieve a polarising filter for the lens I planned to shoot with on an afternoon walk. The bottom of the inside of my ThinkTank camera bag was wet. I got everything out and saw brown liquid trails streaking down one side of the bag. It eventually transpired through monosyllabic answers that my 13 year old had used my camera bag as a picnic table in the back of the car and hadn't screwed the top on his Coke bottle fully before nestling it between the bag's straps.

The camera remained dead. Nikon have just finished the repair for £1,127 ($1,970). My household insurance should cover it. The moral is don't trust anyone anywhere near your gear and develop a nasty, suspicious mind. I have. The only upside is that I get my D800 back tomorrow and that I enjoyed using my D4 for the rest of the holiday.

Well done to all who told me that the problem was condensation - you were very close! I naively though that the footwell behing my seat was the safest place for my camera bag but next time its going in the boot (trunk).

£1127? Holy crap. That's insane. You can buy a new d800 for £1800 now!